#include<stdio.h>
#include<string.h>

int main(int argc, char* argv[])
{
    if(argc!=2)
    {
        printf("Usage: %s [-a][-b][-c]\n",argv[0]);
    }

    const char* arg = argv[1];
    if(strcmp(arg,"-a")==0)
        printf("这是功能1\n");
    else if(strcmp(arg, "-b")==0)
        printf("这是功能2\n");
    else if(strcmp(arg,"-c")==0)
        printf("这是功能3\n");
    else 
        printf("Usage: %s [-a][-b][-c]\n",argv[0]);

    return 0;
}
